The exact amount of time it will take a professional carpet cleaner to clean your house will depend on a lot of things. Naturally, the size of your house itself will influence how fast the carpets can be cleaned.
The nature and toughness of the stain itself will also influence how fast the professional can move from room to room and complete the job. Another factor that can influence this completion time is the cleaning method.
As a professional carpet cleaner, you have access to equipment that makes the job faster but sometimes these methods aren't appropriate for certain situations.
However, if I had to give a rigid estimate based on my time working with services doing Carpet Cleaning in Birmingham, I would say that it may take anywhere between 2 to 6 hours to clean your carpets. You may not need to, but If you can clear out the whole day to focus on this, that would be great.
The following page has more detail if you'd like: https://midlandscarpetcleaners.co.uk/